Telnet SMTP


In this tutorial I am going to show you how to send fake emails by telnetting into the mail server. We will be using the telnet client (which comes with Windows) and you should know about telnet. For learning more about the telnet, please use Google (or I may write a tutorial on it). Sending the forged emails is very easy. We will be connecting to the remote mail server and using the function of mail daemon running in the remote host to send the fake mails.

Anyway, first open the command prompt (start -> run -> cmd)

And type "telnet"

(Without the quotes) then hit enter.. You will be welcomed by Microsoft Telnet.. Now we have to connect the mail daemon through the specific port and the port should have the SMTP service on. Usually, the SMTP port is 25 but that may differ. I also find the port 26 & 587 used frequently for the SMTP service..

For my example, lets say, is providing SMTP mail service through the port 25. First I connect to the mail server by issuing following command in telnet client:

o 25

This establishes a remote connection to the port number 25 at After a successful connection, I am displayed with SMTP server info.. It's always a good idea to ask help from the mail daemon. So first issue HELP to see the supported commands..

Then we introduce ourselves to the mail daemon by issuing the "HELO" command.. and after a successful helo command, we input the sender email using 'mail from:' (without quotes) command.. Then we enter the recipient's address using the 'rcpt to:' (without quotes) command.

Now, we enter our actual data using the DATA command.. Within DATA, you can use SUBJECT: command to enter the subject of email..
Finally, we end our data by entering .(full stop) at the end. This sends the forged mail through that mail server..

Now let me show a session of email forging from which you can be more clear.
First, I open command prompt and go to telnet client by typing telnet.. Below is the session:

Telnet>o 25
220 ESMTP Sendmail Version 8.x.x; Mon, 28 Sept. 2008;
We do not allow to send fake or bulk emails...
250 Hello Nice to meet you..
250 Sender Ok
250 Recipient Ok
354 Enter mail, end with "." on a line by itself..
I am Bill Gates, the chairman of Microsoft. I would like to offer you a job for Microsoft
Corporation. If you are interested to work with Microsoft, then reply at my mail address.
Bill Gates
250 2.0.0 iF3NDLS240106 Message Accepted For Delivery.

This was the session of sending the forged mail from to

I hope you understood the log.. So this was my little tutorial on sending forged emails.. The art of sending forged emails can be extended to send file attachments and to use multiple recipients.. If you have any further queries, feel free to contact me at samar_acharya[at] Any positive or negative comment is heartily welcomed.. I may extend this file into bigger form (including esmtp, file attachments,etc.) Hope you liked my this little basic tutorial on sending the forged emails..


Extra Notes:

You can find out which ports are opened and if mail is enabled on any of those ports by doing an nmap scan of the website. SMTP is a very commonly open port and could be used to spoof emails tricking site users to send you their details or anything else needed.

Tutorial by sam207



Good idea for a tutorial, thanks sam


thanks man..


What if port 25 is blocked


thank u 4 this .............!!!


or you can use tamper data, a firefox addon and try to tamper the data you sent, but before submit you replace it's email with one of your


Is there a tutorial that shows how to do this that shows how to add an attachment


hi sam i tried to mail you but its not delivering...


Could someone suggest a website with port 25 open??I can't seem to find one.